Ask a Bowman Thread.

There's no such thing as 0.7 to 0.8 seconds for Strafe. It's plain 720ms. Pierce does not take 1 second to charge. I believe it is now only 540ms to charge. I don't know why you would make some assumption like Ultimate Strafe always hitting Final Attack. It doesn't matter that you take a defense penalty for each shot of Ultimate Strafe, because you take the exact same penalty for each shot of Pierce. And there is no such thing as this "new booster" that reduces Strafe's speed to 600ms. Please refrain from making baseless assumptions in the future.

Strafe does 1288.8%/s with maxed Sharp Eyes. Pierce does 779.4%/s on the first monster and 935.28%/s on the second monster. If it does still take one second to charge, it does 561.9%/s on the first monster and 674.3%/s on the second monster and Strafe is marginally better for mobs of two in terms of DPS but completely and absolutely irrelevant for training efficiency which is dependent on positioning and hits to kill, not DPS.
Maxed Ultimate Strafe does 2353.75%/s with maxed Sharp Eyes, Marksman's Boost, and Final Attack. Maxed Pierce does 1308.3%/s on the first monster and 1473.1%/s on the second monster. If they have reverted the charge reduction on Pierce in Big Bang, which I do not believe they have, Pierce would only do 958.4%/s on the first monster and 1079.1%/s on the second monster, making Ultimate Strafe marginally better in terms of DPS but still irrelevant to training efficiency.

The only situation where DPS on mobs compared to single target is truly worthwhile in noting is in a bossing scenario where targets will take minutes to kill. It is otherwise more efficient to count the average hits to kill and rate of killing on monsters to be trained on; the %/s difference is so insignificantly small, that it will almost never make a real difference in hits to kill with either skill. Strafe will likely take as much time to kill two monsters as it does for Pierce, unless you are over killing with one of the skills.

Hm, I took like twenty minutes double checking my pomegranate.

Strafe's speed - First shot has a slight delay which makes it around 0.8 secs. Since you're spamming it twice, it makes sense to include the initial delay. Not that it's even relevant; you can never match up strafe to pierce unless you spam it for a couple of seconds

Pierce's speed - Again you forgot the initial skill delay / the delay on releasing the arrow. Unless you can spam three or just one strafe while you shoot pierce, the exact delay is irrelevant. A 0.1 sec delay would mess up the calculation in-game.

Defense penalty: You take a defense penalty for each shot of strafe/ustrafe versus just one for pierce.

"New Booster": Crossbow Booster (formerly known as Booster) now raises your attack speed by 2.

Including buffs: Since buffs apply to both, they're irrelevant. If you take critical into account then strafe might be better in terms of damage stability, but that's not the question being asked.

Pierce reduction: Opomegranate


If I'm going to be exact, I would plot a probability spread of how many shots it takes to down two enemies. If strafe and pierce does the same percent damage (or even strafe doing slightly better) they have the same odds of not downing an enemy in one shot. Since we have the option to use iron arrow or arrow eruption, if pierce fails to take down both enemies we could take them both down on the second shot but strafe will require four shots. I've seen analyses like these and they're very complex so I'm not even going to attempt it.

Reference: http://jisworld.blog18.fc2.com/blog-entry-391.html